Uncorrelated photon pair generation from an integrated silicon nitride resonator measured by time resolved coincidence detection

We measure the joint temporal intensity of signal and idler photon pairs generated by spontaneous four wave mixing in a silicon nitride microresonator by time-resolved coincidence detection. This technique can be applied to any high-Q optical cavity whose photon lifetime exceeds the duration of the pump pulse. We tailor the temporal correlation of photon pairs by using a resonant interferometric coupler, a device that allows us to independently tune the quality factors of the pump and signal and idler resonances.Temporal post-selection is used to accurately measure the temporal emission of the device, demonstrating a purity of 98.67(1)%.